Why do people fast on the Friday of Parshas Chukas?
In Hilchos Tannis the Magen Avraham and Sefer Eliyahu Rabbah (Orach Chaim 580) says that it is the practice of ceartin people to fast on Erev Shabbos Parshas Chukas. The fast is in Memorial for the 24 wagon loads of handwritten Seforim ordered burnt by King Louis in Paris,France in 1242. It was said by Rabbi Hillel Ben Rabbenu Eliezer of Verona, a Talmid(student) of Rabbenu Yonah that this book burning was Hashems way of showing disapproval of the way the Rambam's Sefer Moreh Nevuchim was burnt forty days earlier with the encouragement of leading Rabbonim in Europe, in that very same area because of their disagreement with some of the Rambams ideas in the sefer and in SEFER HAMADA. On a postive note as an outcome Rabbenu Yona wrote the Sharrie Teshuvah as a way to recive forgivness for his part in burning the Seforim.He also adds that on the same day Erev Shabbos Parshas Chukas two major Jewish communities were destroyed during Tach V'tat, the Chmelnitzki uprising.
This still leaves a question Why on Friday of Parshas Chukas, normally fast go based on Dates in the year why here is it based on the Parsha? This is because when it happened, the wise men of the day did a "SHAILAS CHALOM" a dream query and the answer they received was:
יום הפרשה גורם גזירות התורה That is the Parsha caused this to happen,the explanation comes from the first words in Targum(which we know where written with Ruach Hakodesh as indicated in Gemarah Meggilah) of this weeks Parsha .There it says: דא גזרת אורייתא - v’da gezeras ora’yso, meaning, on day vav or the the six day Friday, da gezeras ora’yso this is the gezera (decree), against the Torah (Shibalei Haleket 263,our version of Onkelos is not the same) this is a Gezairah on the Torah itself.The Torah was foretelling this future atrocities,and we now mourn the great loss of Torah that happened on that day.